What could be wrong with my trucks throttle or carburetor?

carburetor, or throttle body? You say it's a carburetor, but then mention changing the TPS, which is a fuel injection sensor. If it's a throttle body, i would suggest it's again something wrong with the TPS. Something else wrong, could be making the TPS fail. If it's a carb, could be something wrong with the accelerator pump, or off-idle fuel circuits. It may not be fuel related at all, could be spark related. I would take it to a shop, and have them hook it up to a lab scope, to see EXACTLY what is going on inside the cylinders.